How to Read Your Water Meter to Find Hidden Leaks
Updated 2025-09-05
Before you begin, turn off all water uses indoors and outdoors. If your main shutoff and meter are in the basement, inspect around the valve, regulator, and nearby joints for moisture while you test.
Identify Your Meter Type
- Analog: sweep hand and small leak triangle that spins with tiny flows.
- Digital: LCD showing flow rate or a drip/leak icon for continuous flow.
The 15-Minute No‑Use Test
- Record the current reading (and photo) of your meter.
- Ensure no faucets, toilets, humidifiers, or irrigation are running.
- Watch the leak triangle/icon for movement. Wait 15 minutes.
- Recheck the reading. Any change with zero use suggests a leak.
Overnight Test (High Confidence)
- Take a reading after the last water use of the night.
- Verify no scheduled uses (ice maker, softener regeneration, irrigation).
- Check again in the morning. Any increase indicates flow overnight.
Interpreting Results
- Continuous movement: ongoing leak (toilet flapper, irrigation valve, slab).
- Occasional bursts: intermittent use (ice maker, softener, humidifier).
- No movement: likely no leak; repeat test if bills remain high.
Next Steps if a Leak Is Detected
- Isolate indoor vs. outdoor by closing basement branch valves (if present) and retesting.
- Shut toilet supply valves one by one; watch if the indicator stops.
- Temporarily close irrigation/backflow supply and retest.
For common culprits, see our visual inspection checklist. To estimate indoor leak costs, open the Running Toilet and Dripping Faucet calculators.